7
Whenever any numerical quantity increases or decreases,
it is customary to refer to this change in percentage terms.
The following example serves to remind you how to
perform calculations involving percentage changes.
Example 2
a) An investment rises from £2500 to £3375. Express the
increase as a percentage of the original.
b) At the
beginning of a year, the population of a small
village
is 8400. If the annual rise in population is 12%, find the
population at the end of the year.
c) In a sale, all prices are reduced by 20%. Find the
sale of a
good originally costing £580.